As a method of forming wiring for various microelectronic devices, processes such as the sputtering method as one of the vacuum processes have been used for a long time, which require a relatively long period of time and/or expensive equipment. As an alternative method for forming electrically conductive wiring, there exists a so-called ink-jet printing method in which a metal ink is used. A recent prior art document discloses an ink for an ink-jet printer capable of forming electrically conductive wiring having low specific resistance at low temperature (for example, at 160° C.) in a short time by the ink-jet printing method, a method of manufacturing electrically conductive wiring with the above ink, and the electrically conductive wiring (Patent Document 1).
Further, focusing on the above wiring formation technology under conditions of low temperature, an attempt has also been made for forming an electronic device on a flexible resin substrate. Meanwhile, although unrelated to wiring formation for various microelectronic devices, the present inventors disclose a method of manufacturing an oxide semiconductor layer, the method including a precursor layer forming step of forming an oxide semiconductor precursor on or above a substrate to form a layer, the oxide semiconductor precursor having a compound of a metal to be oxidized into an oxide semiconductor dispersed in a solution containing a binder (which may include inevitable impurities) consisting of aliphatic polycarbonate; and an annealing step of heating the precursor layer to a first temperature at which 90 wt % or more of the binder is decomposed, and then annealing the precursor layer at a temperature higher than the first temperature and equal to or higher than a second temperature at which the metal binds to oxygen, and an exothermic peak is observed as determined by differential thermal analysis (DTA) of the precursor (Patent Document 2).
Patent Document 1: JP Patent Publication (Kokai) No. 2011-042758A
Patent Document 2: JP Patent No. 5749411